This is the mail archive of the libc-hacker@sourceware.cygnus.com mailing list for the glibc project.

Note that libc-hacker is a closed list. You may look at the archives of this list, but subscription and posting are not open.

Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]

Re: Linux: FPU control word not set when __fpu_control == _dl_fpu_control.

Jakub Jelinek wrote:
> 
> The cost is pretty high. It means any program no matter if it will use FPU
> or not actually touches the FPU unit. On many machines this means a trap
> into the kernel which has to initialize the whole FPU and give it to the
> application and on several archs on the next context switch you have no way
> to find out nothing else in the FPU state was modified, so you have to save
> it.

Ok, I can see the costs now.  Thanks for the heads up.  I'll look for another
way to fix this.
-- 
Scott Bambrough - Software Engineer
REBEL.COM    http://www.rebel.com
NetWinder    http://www.netwinder.org
Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]